Abstract: Systems and methods are disclosed for estimating impulse responses of multiple channels, e.g., multiple antenna sub-array paths of a base station, in a distributed manner. In one embodiment, a method of operation of a Scalable Estimation Ring (SER) processing component in a SER that operates to estimate impulse responses of corresponding channels is provided. In one embodiment, the method includes, during a first iteration of the SER, receiving a feedback signal for the SER processing component and computing an initial estimate of an impulse response of a corresponding channel based on the feedback signal, removing a contribution of the corresponding channel from the feedback signal based on the initial estimate of the impulse response of the corresponding channel to thereby provide a feedback signal for a next SER processing component in the SER, and outputting the feedback signal for the next SER processing component in the SER.

Abstract: Embodiments of a hybrid unit that supports a configurable number of radio units for a base station in a cellular communications network and embodiments of Distributed Digitally Convertible Radio Units (DDCRUs) for use with the hybrid unit are disclosed. In one embodiment, a hybrid unit for a base station in a cellular communications network is provided. The hybrid unit includes an analog hybrid matrix. The analog hybrid matrix includes a number of feeder ports operative to connect to at least one radio unit and up to a number of radio units that are external to and separate from the hybrid unit. In one preferred embodiment, the radio unit(s) is(are) DDCRU(s). The analog hybrid matrix also includes a number of antenna ports operative to connect to at least one and up to a corresponding number of antennas of the base station.

Abstract: Systems and methods are disclosed for estimating impulse responses of multiple channels, e.g., multiple antenna sub-array paths of a base station, in a distributed manner. In one embodiment, a method of operation of a Scalable Estimation Ring (SER) processing component in a SER that operates to estimate impulse responses of corresponding channels is provided. In one embodiment, the method includes, during a first iteration of the SER, receiving a feedback signal for the SER processing component and computing an initial estimate of an impulse response of a corresponding channel based on the feedback signal, removing a contribution of the corresponding channel from the feedback signal based on the initial estimate of the impulse response of the corresponding channel to thereby provide a feedback signal for a next SER processing component in the SER, and outputting the feedback signal for the next SER processing component in the SER.

Abstract: A calibration method for a base station removes distortion in traffic signals incurred in transmit paths of the base station. The transmit paths are coupled to an antenna array for transmitting the traffic signals in a wireless network. The method includes conditioning a traffic signal to reduce a correlation with another traffic signal before the traffic signals enter the transmit paths. For each of the traffic signals, an impairment estimation is performed based on the traffic signals captured before entering the transmit paths and the traffic signals captured before entering the antenna array. An approximate inverse of the impairment estimation is applied to each of the traffic signals before the traffic signals enter the transmit paths.

Abstract: An antenna array of a base station is calibrated using outbound traffic signals. The outbound traffic signals are captured for use as reference signals before the outbound traffic signals enter transmit paths in a radio unit of the base station. The outbound traffic signals are captured for use as a feedback after the outbound traffic signals exit the transmit paths. Each of the reference signals is one of the outbound traffic signals to be transmitted. An impairment estimator estimates the impairment for each of the outbound traffic signals based on the feedback signal and the reference signals. For each transmit path, a set of weights of an all-pass filter is determined, where the all-pass filter has a frequency response that approximates the impairment estimation in an occupied frequency region where reference signal power is above a threshold. The set of weights is inversed to obtain equalizer taps for each of the transmit paths.

Abstract: A method, apparatus, and system for compression of complex data signals within a telecommunications base station. The system may include a transmitter configured to determine a larger value of either real or imaginary components of a digital complex signal. The transmitter designates an exponent of an exponential representation of the larger value as a common exponent to be used for compressing the digital complex signal. The transmitter also compresses a digital complex signal into a series of bits by sharing the common exponent across the real and imaginary components of the digital complex signal, and transmits the series of bits onto a physical medium of the communication system. The system may also include a receiver configured to receive the series of bits from the physical medium, and to expand the series of bits to reconstitute the digital complex signal by again sharing the common exponent across the real and imaginary components of the digital complex signal.

Abstract: An antenna array of a base station is calibrated using outbound traffic signals. The antenna array includes a number of sub-arrays. A combiner in the antenna array combines the outbound traffic signals in the sub-arrays into a feedback signal. The outbound traffic signals are captured simultaneously for use as reference signals before the outbound traffic signals enter transmit paths in a radio unit of the base station. Each of the reference signals is one of the outbound traffic signals that is to be transmitted via one of the sub-arrays. An impairment estimator of the base station estimates the impairment for each of the outbound traffic signals based on the feedback signal and the reference signals. An approximate inverse of the impairment estimation is applied to the outbound traffic signals by a number of equalizers before the outbound traffic signals enter the transmit paths.

Abstract: To provide space division multiple access in a wireless network, plural beams are transmitted within a cell segment. Different information sets are sent in the corresponding plural beams, where one or more of the information sets are detectable by a mobile station depending upon a location of the mobile station in the cell segment. An indication responsive to which of the different information sets is detected by the mobile station is received, and beam selection from among the plural beams is performed according to the received indication.

Abstract: A method and apparatus for compression of complex data signals within a telecommunications base station. The method includes representing a sample of a complex value discrete time signal using 2(L?N)?S mantissa bits and 2N+S exponent bits to realize peak output signal to noise ratios over a wider dynamic range compared to a conventional L-bit uniform quantization format. The increases in dynamic range and peak output SNR is achieved without increasing the average number of data bits per sample and with relatively simple computational effort.

Abstract: Methods and devices for removing cross coupling effects between elements of an antenna array (110) are provided. Cross coupling coefficients between all pairs of antenna elements of the antenna array are predetermined to minimize a total power in theoretical null points calculated without considering the cross element effects. A transceiver (100) includes a multiplexing block (105) configured to receive data signals to be transmitted via the antenna elements and to output to at least one of the antenna elements, a sum signal including (i) a data signal, which data signal is designated for the at least one antenna element, and (ii) a linear combination of data signals designated for other antenna elements of the antenna array, each of the data signals in the linear combination being weighted by a respective cross coupling coefficient between the at least one antenna element and an antenna element emitting the each of the data signals.

Abstract: A method and system adaptively reduce a peak-to-average power ratio in a communication system. Energy is clipped from at least one peak of a modulated signal. The modulated signal includes a plurality of sub-carriers. At least one data sub-carrier is adaptively selected for peak-to-average power ratio reduction use based on known scheduling information. The clipped energy is distributed among at least one data sub-carrier.

Abstract: A fluorescent bulb compactor and mercury vapor recovery system that allows for the safe collection and disposal of crushed or broken fluorescent lamps, while recovering substantially 100% of the hazardous mercury vapors contained within the lamps. A fluorescent lamp is inserted within a drum and broken into fragments by one or more blades, with the fragment falling to the bottom of the drum. The mercury vapors that are emitted from the broken fluorescent lamps are forced out of the drum by negative positive pressure created by a vacuum/filter assembly. Once through the filter assembly, which includes a HEPA filter and activated carbon filter, the gases are permitted to escape into the environment virtually 100% free of mercury toxins.

Abstract: A system and method are provided for frequency domain peak power reduction on a plurality of orthogonal frequency divisional multiplexing (OFDM) signals in a communications system, wherein frequency domain processing of at least one OFDM signal carrier is iteratively performed to reduce peak power transmissions. OFDM signal carriers can include both in-band sub-carrier signals, and guard-band sub-carrier signals. Each iteration of peak power reduction takes as an input the frequency domain representation of the signal from the previous iteration that has been altered with respect to an error signal also represented in the frequency domain, determines an error signal (in the frequency domain), and subtracts this from the input to produce a further peak power reduced frequency domain signal. If there are no peaks above the configured peak power reduction threshold, then the signal passes through the FPPR iterations with no change.

Abstract: A spectrum agile radio having one or more variable digital filters is described. To quickly, yet accurately, retune the digital filter(s) a windowing function is applied to an ideal filter characteristic for each of one or more desired frequency bands to generate filter coefficients. Transitioning between coefficients of a previous filter and a current filter is handled to avoid problems associated with discontinuities in the signal processing.

Abstract: A method and system for achieving peak power reduction in the radio are disclosed. According to one aspect, universal peak power reduction is used to perform peak power reduction on time domain signals, such as CDMA, WCDMA and GSM, as well as frequency domain signals, such as OFDM signals used in long-term evolution, LTE, systems, and on combinations of time and frequency domain signals. Processing is performed on a segment of data at a time. The size of the segment of data chosen is based on a desired latency, frequency resolution and peak power reduction performance in a given system.

Abstract: Disclosed is a system and method for peak power reduction on a plurality of frequency domain orthogonal frequency divisional multiplexing (OFDM) signal carriers and a plurality of time domain signal carriers in a communications system. The system includes a plurality of frequency domain carrier processing blocks configured to iteratively perform frequency domain processing of at least one frequency domain OFDM signal carrier to reduce peak power transmission and a plurality of time domain carrier processing blocks configured to iteratively perform time domain processing of at least one time domain signal carrier to reduce peak power transmission, wherein the system is further configured to perform the frequency domain processing and time domain processing substantially simultaneously, thereby spreading excess peak power to one or more of the plurality of frequency domain OFDM signal carriers and to one or more of the plurality of time domain signal carriers.

Abstract: Methods and devices for extracting a RACH preamble using as input a number of Fast Fourier Transformed symbols, in order to extract a random access channel (RACH) preamble from a signal received in a base station from a user device, in a radio communication system, are provided. An initial cyclic prefix (symbol CP) is removed prior to performing FFT on symbols. After (1) selecting from the FFT of a symbol frequencies corresponding to the RACH band all other non-RACH frequency bins having been set to zero, (2) shifting the signal to baseband and (3) performing a FFT on the baseband signal, a phase adjustment is performed to compensate for group delays due to symbol CP gaps occurring when generating the baseband signal, the phase adjustment being determined individually for each symbol.

Abstract: Embodiments of a hybrid unit that supports a configurable number of radio units for a base station in a cellular communications network and embodiments of Distributed Digitally Convertible Radio Units (DDCRUs) for use with the hybrid unit are disclosed. In one embodiment, a hybrid unit for a base station in a cellular communications network is provided. The hybrid unit includes an analog hybrid matrix. The analog hybrid matrix includes a number of feeder ports operative to connect to at least one radio unit and up to a number of radio units that are external to and separate from the hybrid unit. In one preferred embodiment, the radio unit(s) is(are) DDCRU(s). The analog hybrid matrix also includes a number of antenna ports operative to connect to at least one and up to a corresponding number of antennas of the base station.

Abstract: An antenna array of a base station is calibrated using outbound traffic signals. The outbound traffic signals are captured for use as reference signals before the outbound traffic signals enter transmit paths in a radio unit of the base station. The outbound traffic signals are captured for use as a feedback after the outbound traffic signals exit the transmit paths. Each of the reference signals is one of the outbound traffic signals to be transmitted. An impairment estimator estimates the impairment for each of the outbound traffic signals based on the feedback signal and the reference signals. For each transmit path, a set of weights of an all-pass filter is determined, where the all-pass filter has a frequency response that approximates the impairment estimation in an occupied frequency region where reference signal power is above a threshold. The set of weights is inversed to obtain equalizer taps for each of the transmit paths.

Abstract: An antenna array of a base station is calibrated using outbound traffic signals. The antenna array includes a number of sub-arrays. A combiner in the antenna array combines the outbound traffic signals in the sub-arrays into a feedback signal. The outbound traffic signals are captured simultaneously for use as reference signals before the outbound traffic signals enter transmit paths in a radio unit of the base station. Each of the reference signals is one of the outbound traffic signals that is to be transmitted via one of the sub-arrays. An impairment estimator of the base station estimates the impairment for each of the outbound traffic signals based on the feedback signal and the reference signals. An approximate inverse of the impairment estimation is applied to the outbound traffic signals by a number of equalizers before the outbound traffic signals enter the transmit paths.